Light-emitting device having optoelectronic elements on different elevations

ABSTRACT

The present application provides a multi-dimensional light-emitting device electrically connected to a power supply system. The multi-dimensional light-emitting device comprises a substrate, a blue light-emitting diode array and one or more phosphor layers. The blue light-emitting diode array, disposed on the substrate, comprises a plurality of blue light-emitting diode chips which are electrically connected. The multi-dimensional light-emitting device comprises a central area and a plurality of peripheral areas, which are arranged around the central area. The phosphor layer covers the central area. When the power supply system provides a high voltage, the central area and the peripheral areas of the multi-dimensional light-emitting device provide a first light and a plurality of second lights, respectively. The first light and the second lights are blended into a mixed light.

TECHNICAL FIELD

The application relates to a multi-dimensional light-emitting device,and more particularly to a light-emitting device adapted to astandardized power supply system.

REFERENCE TO RELATED APPLICATION

This application claims the right of priority based on Taiwanapplication Ser. No. 099123630, filed Jul. 19, 2010, and Taiwanapplication Ser. No. 100106620, filed Feb. 25, 2011, and the content ofwhich is hereby incorporated by reference in its entirety.

DESCRIPTION OF BACKGROUND ART

With the rapid development of the technology, the light-emitting diode(LED) is widely applied to display device, traffic signals, lighting,medical devices and various electronic products.

There are several ways using LEDs to produce white light: (1) mixingblue light, red light, and green light which are respectively generatedfrom blue, red, and green LED(s) to produce the white light; (2) usingultraviolet light-emitting diode(s) exciting phosphor to produce thewhite light; and (3) using blue LED(s) exciting yellow phosphor toproduce the white light by the complementary colors.

Some issues still remain in the aforementioned ways; therefore, themarket is looking forward to the technology innovations.

SUMMARY OF THE DISCLOSURE

One purpose of the present application is to provide a multi-dimensionallight-emitting device adapted to a standardized power supply system, andhas low cost, low electric power consumption, and good color rendering.

To achieve the above purpose, a multi-dimensional light-emitting deviceis provided to be electrically connected to a standardized power supplysystem such as power line, network, telephone line, and industrial powersupply. The multi-dimensional light-emitting device includes a carrier,a first optoelectronic element, and second optoelectronic elements. Asurface of the carrier can have a first region and second regions whichare near the first region. The first optoelectronic element is arrangedon the first region; and the second optoelectronic elements are arrangedon the second regions. However, the materials, the structures, thequantities, the light colors, the color temperatures, the intensities,and the luminous efficiencies of the second optoelectronic elements onthe second regions are not limited to the same. The standardized powersupply system is electrically connected to the first optoelectronicelement and the second optoelectronic elements. The first optoelectronicelement can emit a first light; at least part of the secondoptoelectronic elements can emit a second light which can be mixed withthe first light to produce a mixed light. In one embodiment, the firstlight, the second light, and the mixed light are blue light, red light,and (warm) white light, respectively. In another embodiment, at leastone of the first light and the second light is mixed by several colorlights. For example, the first light is mixed by blue light and yellowlight, and/or the second light is mixed by blue light and red light. Ina further embodiment, at least two of the second optoelectronic elementscan emit second lights having different colors. For example, one secondoptoelectronic element can emit red light; another second optoelectronicelement can emit green light or yellow light.

In one embodiment, the first optoelectronic element includes a bluelight-emitting diode array and a first wavelength converter such as aphosphor, a semiconductor, and a dye. The blue light-emitting diodearray includes blue light-emitting diode chips which can be connected inseries, parallel, or a combination thereof. The first wavelengthconverter can be overlaid on the blue light-emitting diode array. Inaddition, the second optoelectronic element can be a red light-emittingdiode chip, a red light-emitting diode array, a combination of a bluelight-emitting diode chip and a red wavelength converter, or acombination of a blue light-emitting diode array and a red wavelengthconverter.

In a further embodiment, a multi-dimensional light-emitting device iselectrically connected to a standardized power supply system. Themulti-dimensional light-emitting device includes a carrier, a bluelight-emitting diode array, a first wavelength converter, and secondwavelength converters. The blue light-emitting diode array is arrangedon the carrier and includes blue light-emitting diode chips which areelectrically connected with each other. The blue light-emitting diodearray has a central area and peripheral areas surrounding the centralarea. However, one peripheral area may overlap the central area and/oranother peripheral area. The first wavelength converter can cover atleast part of the central area. Each second wavelength converter cancover at least part of one peripheral area. Moreover, the wavelengthconverters may overlap with each other. The area or the wavelengthconverter can meet the required color temperature, hue, light field,light intensity, luminous efficiency, or other criteria by adjusting thelayout, the position, the area, the thickness, and/or the concentration.The standardized power supply system is electrically connected to theblue light-emitting diode array such that the central area and at leastone of the peripheral areas respectively produce a first light and asecond light which can be mixed with the first light to produce a mixedlight. In other words, the peripheral areas can produce light at thesame time or different times.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate a multi-dimensional light-emitting device inaccordance with one embodiment of the present application.

FIG. 2 illustrates a multi-dimensional light-emitting device inaccordance with another embodiment of the present application.

FIG. 3 illustrates a multi-dimensional light-emitting device inaccordance with one embodiment of the present application.

FIG. 4 illustrates a multi-dimensional light-emitting device inaccordance with a further embodiment of the present application.

FIGS. 5A and 5B illustrate a multi-dimensional light-emitting device inaccordance with one embodiment of the present application.

FIGS. 6A to 6E illustrate multi-dimensional light-emitting devices inaccordance with embodiments of the present application.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The embodiments are described hereinafter in accompany with drawings.However, the embodiments of the present application are not to limit thecondition(s), the application(s), or the mythology. The embodiments canbe referred, exchanged, incorporated, collocated, coordinated exceptthey are conflicted, incompatible, or hard to be put into practicetogether. Moreover, the drawing(s) are generally illustrated insimplified version(s). The element(s), quantities, shape(s), or othercharacteristic(s) are not to limit the specific application.

Firstly, referring to FIG. 1A, a multi-dimensional light-emitting device10 in accordance with one embodiment of the present application isillustrated. The multi-dimensional light-emitting device 10 can beelectrically connected to a standardized power supply system 1 such aspower line, network, telephone line, and industrial power supply. Themulti-dimensional light-emitting device 10 includes conductive lines 10a, electrodes 10 b, a carrier 12, a first optoelectronic element 14,second optoelectronic elements 16, and heat dissipation structures 18.As shown in FIG. 1B, the carrier 12 can be partitioned into a firstregion 12 a and four second regions 12 b. The four second regions 12 bsurround the first region 12 a in a configuration such as randomdistribution, mirror symmetry, rotational symmetry, and radial symmetry.

The first optoelectronic element 14 includes a blue light-emitting diodearray 14 a and a first wavelength converter 14 b. The bluelight-emitting diode array 14 a includes several blue light-emittingdiodes (not shown). The blue light-emitting diodes are arranged in amulti-dimensional configuration such as zigzag type, crossing type,and/or U type. The blue light-emitting diodes can be electricallyconnected with each other in series, parallel, or a combination thereof.By the multi-dimensional configuration, the light-emitting diode array14 a has an operation voltage and/or an operation current being higherthan a single chip. The array 14 a can be directly connected to thestandardized power supply system 1, or connected to the standardizedpower supply system 1 in combination with a second optoelectronicelement 16. Specifically, one or more light-emitting diode array 14 a,which are connected with each other in series, can be optionallyconnected to the second optoelectronic element 16, a resister, acapacitor, and/or an inductor in series, parallel, or a combination ofseries and parallel, and then connected to the standardized power supplysystem 1. For example, the standardized power supply system 1 canprovide a voltage of X volt. One light-emitting diode array 14 a canaccept a voltage equal to or near X//N volt (N is any integer). ProvidedN light-emitting diode arrays 14 a are connected in series, the arrayscan work at X volt.

The blue light-emitting diode array 14 a can be arranged on the firstregion 12 a of the carrier 12 through a suitable connecting material(not shown). The first wavelength material 14 b is arranged to overlaythe blue light-emitting diode array 14 a. Preferably, the firstwavelength converter 14 b is a yellow wavelength converter such as ayellow phosphor, a yellow dye, and/or a yellow filter. The yellowphosphor is such as YAG, TAG, nitride phosphor, and silicate phosphor.

In the present embodiment, at least one of the four secondoptoelectronic elements 16 in FIG. 1A, which includes a redlight-emitting diode array (i.e. including several red light-emittingdiode chips) or a red light-emitting diode chip, is arranged on thesecond region 12 b of the carrier 12 by a suitable connecting material(not shown). Preferably, to prevent the red light-emitting diode arrayfrom absorbing the light from the blue light-emitting diode array 14 aor being deteriorated by the heat from the blue light-emitting diodearray 14 a, the blue light-emitting diode array 14 a and the redlight-emitting diode array are separated from each other by a suitabledistance. The distance is greater than 0.5 mm, 1 mm, 2.0 mm, 3.0 mm, 4.0mm, 5.0 mm, 1.0 cm, 2.0 cm, 3.0 cm, 4.0 cm, or 5.0 cm. Furthermore, thered light-emitting diode array or chip can be operated under a voltagesmaller than, equal to, close to, or greater than that of the bluelight-emitting diode array 14 a.

The standardized power supply system 1 can be electrically connected toeach of the electrodes 10 b of the multi-dimensional light-emittingdevice 10. As shown in FIG. 1A, the electrodes 10 b, the firstoptoelectronic element 14, and the second optoelectronic elements 16 areelectrically connected with each other by several conductive lines 10 a.The standardized power supply system 1 can make the first optoelectronicelement 14 and each of the second optoelectronic elements 16 to emit afirst light and a second light respectively in order to produce a mixedlight. The mixed light has a color temperature equivalent to acandlelight of 1500K˜2500K, an incandescent lamp of 2500K˜3500K, a highintensity discharge lamp of 4500K˜5000K, and/or a flash light of5500K˜5600K. The color temperature of less than 3300K is usually calledas “warm white”; the color temperature between 3300K and 5300K isusually called as “cool white”; the color temperature of more than 5300Kis usually called as “cool color light”. A variety of color temperaturesin the mixed light can be achieved by using the design principleillustrated in the embodiments of the present application.

In comparison with the blue light-emitting diode, the efficiency of thered light-emitting diode remarkably decreases when the temperatureincreases. As shown in FIG. 1A, to lower the temperature of the redlight-emitting diode array or chip, a heat dissipation structure 18 isfurther arranged under the red light-emitting diode array or chip of thesecond optoelectronic element 16 in accordance with one embodiment ofthe present application. The heat dissipation structure 18 is such asfin(s), fan(s), heat pipe(s), and liquid cooler, high thermalconductivity material bulk(s), porous material(s), and a combinationthereof.

To display the mixed light in a uniform color and/or high colorrendering, the first optoelectronic element 14 and the secondoptoelectronic element 16 can be configured such that each element meetsits electrical property (such as energy efficiency, and power factor),optical property (such as light field, light intensity, hot/coldfactor), and/or geometric shape. In accordance with an embodiment of thepresent application, a light-emitting area ratio of the firstoptoelectronic element 14 to all second optoelectronic elements 16 isbetween 2:1 to 5:1 on the carrier 12. However, the light-emitting arearatio of a single first optoelectronic element 14 to a single secondoptoelectronic element 16 is not limited to the aforementioned range. Inanother embodiment of the present application, a power ratio of thefirst optoelectronic element 14 to all second optoelectronic elements 16is between 2 and 5, however, the ratio of a single first optoelectronicelement 14 to a single second optoelectronic element 16 is not limitedto the aforementioned range. In addition, provided one element candeteriorate another element by its light, heat, magnetic field, and/orelectric field, the distance between the elements or the layout ofelements is preferably configured to reduce or remove the deterioration.For example, the material with low energy band gap can absorb highenergy light. The material with high hot/cold factor has lowerlight-emitting efficiency at high temperature. A counter magnetic fieldhinders the combination of electrons and holes. In one embodiment of thepresent application, for example, the neighboring elements in themulti-dimensional light-emitting device 10 are separated from each otherby a distance or tilted with each other in an angle such that there isno or least overlap between the elements' light fields, which renders auniform color distribution.

In an embodiment, the first optoelectronic element 14 and the secondoptoelectronic element 16 are electrically connected to the standardizedpower supply system 1 in series. The blue light-emitting diode array 14a, and the red light-emitting diode array or chip, therefore, can beoperated at high voltage and low current (in comparison withnon-light-emitting diode array), such that less energy loses during theenergy transmission and conversion, and a simple circuit between thestandardized power supply system 1 and the multi-dimensionallight-emitting device can be used. The elements of the presentapplication can be also connected in parallel or a combination of seriesand parallel.

In another embodiment, the material of the carrier 12 can be a singlecrystal, a poly crystal, or non-crystal, such as glass, sapphire, SiC,GaP, GAAsP, ZnSe, ZnS, AmSSe, and AlN.

Moreover, in the first optoelectronic element 14, gallium nitride (GaN)series chips can be used in the blue light-emitting diode array 14 a toemit blue light with a wavelength of 400 nm˜530 nm (or 455 nm˜465 nm). Ayellow phosphor, such as yttrium aluminum garnet (YAG), can be used asthe first wavelength converter 14 b. In another embodiment, other yellowphosphors (such as TAG, nitride series phosphor, silicate seriesphosphor), fluorescent plate, semiconductor, and dye can also be used.In the second optoelectronic element 16, AlGaInP series chip can be usedin the red light-emitting diode array to emit red light with awavelength of 600 nm˜750 nm (or 620 nm˜625 nm). The material of the heatdissipation structure can be selected from high conductivity materialssuch as copper (Cu), aluminum (Al), and silicon (Si). The heatdissipation structure can also be made of ceramic material(s). However,the aforementioned materials are only illustrative, and not to limit thescope of the present invention. The color light can have various colortemperature by adjusting the quantity or the light intensity of the bluelight-emitting diode array 14 a, the thickness or the concentration ofthe wavelength converter, and/or the mixture ratio of the blue light tothe red light.

Referring to FIG. 2, a multi-dimensional light-emitting device inaccordance with a further embodiment of the present application isdisclosed. A multi-dimensional light-emitting device 20 is electricallyconnected to a standardized power supply system 2. The multi-dimensionallight-emitting device 20 includes a carrier 22, a first optoelectronicelement 24, and second optoelectronic elements 26. The firstoptoelectronic element 24 includes a blue light-emitting array 24 a anda first wavelength converter 24 b. The second optoelectronic element 26includes a blue light-emitting array 26 a and a second wavelengthconverter 26 b. The first wavelength converter 24 b includes one yellowwavelength converter. The second wavelength converter 26 b includes onered wavelength converter.

In addition, in the present embodiment, the first wavelength converter24 b and the second wavelength converter 26 b can be arranged onseparate elements, or stacked on the same element. Both of the firstoptoelectronic element 24 and the second optoelectronic element 26 areblue light-emitting diode arrays, therefore, light absorption among theelements can be prevented. Moreover, the distance between the bluelight-emitting diode arrays of the optoelectronic elements can be asshort as possible in order to reduce the packaging area.

FIG. 3 is a perspective view of a multi-dimensional light-emittingdevice 30 in accordance with an embodiment of the present application.

The multi-dimensional light-emitting device 30 in the present embodimentis also electrically connected to a standardized power supply system 3.The multi-dimensional light-emitting device 30 includes conductive lines30 a, two electrodes 30 b, a carrier 32, a first optoelectronic element34, and four second optoelectronic elements 36.

In detail, a blue light-emitting diode array is used to excite the firstwavelength converter 34 b of a red phosphor in the first optoelectronicelement 34 of the present embodiment. A green light-emitting diode arrayhaving several green light-emitting diode chips is used in the secondoptoelectronic element 36. However, a single green light-emitting diodechip may be used in other embodiments.

The standardized power supply system 3 is electrically connected to themulti-dimensional light-emitting device 30 and provides a standardizedvoltage and/or current. The first optoelectronic element 34 and thesecond optoelectronic element 36 can emit a first light and a secondlight. The first light can be mixed with the second light to produce amixed light. The mixed light can include a blue light, a red light, anda green light. Various color lights, such as warm white, cool white, andother color light which can be generated by a mixture of primary colors,can be produced by mixing the three colors in different proportion.Furthermore, the percentage of the blue light in the mixed light can beclose to 0, less than 5%, or less than 1%, if most or all of the bluelight is used in generating red light.

FIG. 4 illustrates a multi-dimensional light-emitting device 40 inaccordance with another embodiment of the present application. Themulti-dimensional light-emitting device 40 is electrically connected toa standardized power supply system 4. In the present embodiment, a bluelight-emitting diode array 42 a is used to excite a first wavelengthconverter 42 b of a red phosphor to generate a first light in the firstoptoelectronic element 42. In the second optoelectronic element 44, ablue light-emitting diode array 44 a is used to excite a greenwavelength converter 44 b positioned above to generate a second lightwhich can be mixed with the first light into a mixed light. In such anarrangement, various visible lights can be produced by mixing the bluelight, red light, and green light in different proportions. However, theblue light may be hardly perceivable in the mixed light, if most or allof the blue light is used to generate the red light and the green light.

In the present embodiment, the first wavelength converter 42 b and thesecond wavelength converter 44 b can be arranged on separate elements,or stacked on the same element. Both of the first optoelectronic element42 and the second optoelectronic element 44 are blue light-emittingdiode arrays, therefore, light absorption among the elements can beprevented. Moreover, the distance between the blue light-emitting diodearrays of the optoelectronic elements can be as short as possible inorder to reduce the packaging area.

In the aforementioned embodiments, provided the blue light-emittingdiode arrays are used in the first region and the second region, thedistance between the first region and the second region can be reduceddue to the low absorption rate of the blue light-emitting diode whenbeing exposed to other wavelength(s), such as those in the twoaforementioned embodiments. However, provided different colorlight-emitting diode arrays, such as blue and red light-emitting diodes,or blue and green light-emitting diodes, are used in the first regionand the second region, a longer distance is preferable, because the redlight-emitting diode or the green light-emitting diode has a higherabsorption rate to other wavelength. Besides, the light-emitting diodearray in the second region may be replaced by a single chip.

FIG. 5A illustrates a multi-dimensional light-emitting device 50 inaccordance with a further embodiment of the present application. Themulti-dimensional light-emitting device 50 is electrically connected toa standardized power supply system (not shown). The multi-dimensionallight-emitting device includes a carrier 52, a blue light-emitting diodearray 54, a first wavelength converter 56, and four second wavelengthconverters 58.

The blue light-emitting diode array 54 is arranged on the carrier 52 andhas several blue light-emitting diode chips (not shown). The severalblue light-emitting diode chips are electrically connected with eachother in series, parallel, or a multi-dimensional configuration ofseries and parallel connections. As shown in FIG. 5B, the bluelight-emitting diode array 54 has a central area 54 a and fourperipheral areas 54 b surrounding the central area 54 a. As shown inFIG. 5A, the first wavelength converter 56 is overlaid on the centralarea 54 s; the four second wavelength converter 58 are respectivelyoverlaid on the four peripheral areas 54 b.

In the present embodiment, the material selections and the practices ofthe carrier 52, the blue light-emitting diode array 54, the firstwavelength converter 52 a, and the second wavelength converter 52 a canbe referred to the aforementioned descriptions.

The standardized power supply system is electrically connected to theblue light-emitting diode array 54. A first light and a second light canbe respectively generated from the central area 54 a and the peripheralareas 54 b of the blue light-emitting diodes array 54. The first lightcan be mixed with the second light to produce a mixed light.

FIG. 6A illustrates a multi-dimensional light-emitting device 60 inaccordance with a further embodiment of the present application. Themulti-dimensional light-emitting device 60 is electrically connected toa standardized power supply system 6. The multi-dimensionallight-emitting device 60 includes conductive lines 60 a, two electrodes60 b, a carrier 62, four first optoelectronic elements 64, a secondoptoelectronic element 66, and a heat dissipation structure 68. As shownin FIG. 6B, the carrier 62 has four first regions 62 a and a secondregion 62 b. The first regions 62 a surround the second region 62 b.

Referring to FIGS. 6A and 6B, each first optoelectronic element 64includes a blue light-emitting diode array 64 a (in the presentapplication, all or part of the blue light-emitting diode array can bereplaced by a blue light-emitting diode chip), and a first wavelengthconverter 64 b. The blue light-emitting diode array 64 a includesseveral blue light-emitting diode chips (not shown). The bluelight-emitting diode chips can sustain a forward voltage and/or acurrent higher than that of a single semiconductor light-emittingepitaxial structure by connecting with each other in a multi-dimensionalconfiguration (such as zigzag type, crossing type, and U type) ofseries, parallel, or a combination of series and parallel. Four of theblue light-emitting diode arrays 64 a are mounted on the four firstregions 62 a of the carrier 62 by a mounting material (not shown). Thefirst wavelength converter 64 b is overlaid on the blue light-emittingdiode array 64 a. The first wavelength converter 64 b can emit light ofyellow, red, or green.

As shown in FIG. 6A, the second optoelectronic element 66 in the presentembodiment includes a red light-emitting diode array (or a single redlight-emitting diode chip) arranged on the second region 62 b of thecarrier 62. The blue light-emitting diode array 64 a is separated fromthe red light-emitting diode array by a suitable distance, such that thered light-emitting diode array is prevented from absorbing the lightfrom the blue light-emitting diode array 64 a. In addition, provided theblue light-emitting diode array, the red light-emitting diode array, orboth are arranged in a lower structure which can obstruct the lighttransmission, or have a larger margin which can increase a distancebetween two neighboring light-emitting diode arrays, or have anobstructing structure between the blue and red light-emitting diodearrays. For example, a light obstructer 69 can prevent the redlight-emitting diode array from absorbing the light from the bluelight-emitting diode array 64 a.

The standardized power supply system (not shown) can be electricallyconnected to each of electrodes 60 b of the multi-dimensionallight-emitting device 60. As shown in FIG. 6A, the electrode(s) 60 b,the first optoelectronic element(s) 64, and the second optoelectronicelement(s) 66 are series-connected by conductive lines 60 a. The firstoptoelectronic element(s) 64 and the second optoelectronic element(s) 66can respectively emit a first light and a second light. The two lightscan be mixed into a mixed light. Preferably, the color temperature ofthe mixed light is ranged between 2500K and 3800K, more preferably, thecolor temperature is about 3000K or in a range of warm white.

The luminous efficiency of the red light-emitting diode apparentlydecays more when the temperature rises. Therefore, as shown in FIG. 6A,a heat dissipation structure 68, which can cool the red light-emittingdiode array, is arranged under the red light-emitting diode array, i.e.between the second optoelectronic element 66 and the carrier 62, suchthat the issue of the power decaying at high temperature can berelieved. The heat dissipation structure 68 is such as fin(s), fan(s),heat pipe(s), liquid cooler(s), high conductivity material(s), andporous material(s). Besides, the heat dissipation structure 68 can beoptionally arranged on a position higher than a blue light-emittingdiode array 64 a, such that, when an optical lens is arranged on themulti-dimensional light-emitting device 60, more light can be extractedfrom the second optoelectronic element 66 which is positioned near anoptical axis of the optical lens but not in the periphery of themulti-dimensional light-emitting device 60 (such as in the embodimentsof FIGS. 1A-4). The first wavelength converter 64 b can includeparticle(s) which can scatter light (such as phosphors, scatteringparticles). In this case, even though the first optoelectronic elements64 are arranged on the periphery of the multi-dimensional light-emittingdevice 60, the light can still be extracted outwards by the particles.

To produce light having uniform color and/or good rendering, the firstoptoelectronic element(s) 64 and the second optoelectronic element 66are arranged on the carrier 62 by a light-emitting area ratio of 2:1˜5:1(the related drawings are only for illustrative, but not to reflect theactual scale.). Optionally, in one embodiment, the power ratio of bluelight of the first optoelectronic element(s) 64 to the red light of thesecond optoelectronic element(s) 66 is ranged between 2 and 5.

In one embodiment, the first optoelectronic element 64 and the secondoptoelectronic element 66 are electrically connected to the standardizedpower supply system in series, such that the blue light-emitting diodearray 64 a and the red light-emitting diode array can be operated at ahigh voltage and a low current, which can bring to a low energyconsumption operation (in comparison with non-light-emitting diodearray) and a simple circuit between the standardized power supply systemand the multi-dimensional light-emitting device. However, the elementsin the application can also be connected in parallel or a combination ofseries and parallel.

FIG. 6C illustrates a multi-dimensional light-emitting device 60 inaccordance with another embodiment of the present application. Asdescribed above, the luminous efficiency of the multi-dimensionallight-emitting device 60 may decrease, if the material of the secondoptoelectronic element 66 absorbs the light from the firstoptoelectronic element 64. In the present embodiment, the carrier 62 hasa lower structure 70 in which the second optoelectronic element 66 ispositioned. The lower structure 70 can obstruct light moving between thefirst optoelectronic element 64 and the second optoelectronic element66, such that the second optoelectronic element 66 has lower possibilityof absorbing the light from the first optoelectronic element 64. Theluminous efficiency of the multi-dimensional light-emitting device istherefore alleviated. The lower structure 70 can be formed to be a oneopen-ended channel or a multi-open-ended channel, such as a blind holeand a trench.

Furthermore, a reflective layer 71 can be arranged on the lowerstructure 70. The light from the second optoelectronic element 66 hashigher possibility to leave the lower structure 70 after being reflectedby the reflective layer 71. In other words, the light from the secondoptoelectronic element 66 is not easily trapped in the lower structure70. In addition, a transparent material 72 can be filled into the lowerstructure 70 to cover the second optoelectronic element 66. Thetransparent material 72 is transparent to the light from the secondoptoelectronic element 66 and can protect the second optoelectronicelement 66 from being effected by external force, humidity, and/ortemperature. The transparent material 72 can be also functioned as anoptical lens if it is molded in a specific shape. The optical lens issuch as a convex, a concave, and a Fresnel lens.

As shown in FIG. 6D, in another embodiment, a covering structure 73 canbe arranged on the first optoelectronic element 64 and the secondoptoelectronic element 66. The covering structure 73 can protect theelement(s) therein. The lights from the first optoelectronic element 64and the optoelectronic element 66 can be mixed in the covering structure73. The covering structure 73 is formed of transparent material(s) whichcan include scattering structure(s), and/or light convertingstructure(s). A pertinent document can be referred to Taiwan patentapplication Ser. No. 099141373, and the content of which is herebyincorporated by reference.

As shown in FIG. 6E, a heat insulation structure 74 can be formedbetween the first optoelectronic element 64 and the secondoptoelectronic element 66. The first optoelectronic element 64 usuallyhas a temperature coefficient different from the second optoelectronicelement 66. For example, as described above, compared with the bluelight-emitting diode, the luminous efficiency of the red light-emittingdiode apparently decays more when the temperature rises. The heatinsulation structure 74 is beneficial to prevent thermal interactionbetween the optoelectronic elements, especially a heat transporting froma high temperature element to low temperature element. The heatinsulation structure 74 can surround one or more elements of the samekind. For example, the heat insulation structure 74 can surround one ormore first optoelectronic elements 64, or one or more secondoptoelectronic elements 66. The heat insulation structure 74 can bearranged in the carrier 62 to thermally separate the firstoptoelectronic element 64 and the second optoelectronic element 66, asshown in FIG. 6E. However, the heat insulation structure 74 can be alsoarranged under the optoelectronic element to block the heat fromtransmitting downwards or transmitted upwards. For example, the heatinsulation structure 74 can be arranged between the reflective layer 71and the carrier 62, or between the optoelectronic element and thecarrier 62.

The foregoing description has been directed to the specific embodimentsof this invention. It will be apparent; however, that other alternativesand modifications may be made to the embodiments without escaping thespirit and scope of the invention.

What is claimed is:
 1. A light-emitting device, comprising: a firstoptoelectronic element configured to emit a first light and comprising:a blue light-emitting diode chip having a first bottom surface; and afirst wavelength converter arranged on the blue light-emitting diodechip; and a plurality of second optoelectronic elements configured toemit a second light having a wavelength longer than that of the firstlight and having a second bottom surface lower than the first bottomsurface; wherein at least one of the plurality of second optoelectronicelements has a temperature coefficient different from that of the bluelight-emitting diode chip, and wherein the first light can be mixed withthe second light to produce a mixed light having a color temperaturebetween 2500K and 3800K.
 2. The light-emitting device of claim 1,further comprising a carrier which comprises a first region on which thefirst optoelectronic element is arranged, and a second region on whichthe plurality of second optoelectronic elements is arranged.
 3. Thelight-emitting device of claim 2, wherein the first region substantiallysurrounds the second region.
 4. The light-emitting device of claim 2,wherein the first region comprises a single-open-end channel or amulti-open-end channel.
 5. The light-emitting device of claim 2, furthercomprising a reflective layer arranged on the second region.
 6. Thelight-emitting device of claim 2, further comprising a transparentmaterial arranged on the second region and covering the plurality ofsecond optoelectronic elements.
 7. The light-emitting device of claim 6,wherein the transparent material is configured to function as an opticallens.
 8. The light-emitting device of claim 1, further comprising acovering structure arranged on the first optoelectronic element and theplurality of second optoelectronic elements.
 9. The light-emittingdevice of claim 8, wherein the covering structure comprising ascattering structure or a light converting structure.
 10. Thelight-emitting device of claim 1, further comprising a thermalinsulation structure arranged between the first optoelectronic elementand the plurality of second optoelectronic elements.
 11. Thelight-emitting device of claim 10, further comprising a carrier wherethe thermal insulation structure is formed.
 12. The light-emittingdevice of claim 10, wherein the thermal insulation structuresubstantially surrounds the plurality of second optoelectronic elements.13. The light-emitting device of claim 1, wherein the firstoptoelectronic element further comprises a plurality of bluelight-emitting diode chips electrically connected to each other inseries.
 14. The light-emitting device of claim 1, wherein the pluralityof second optoelectronic elements are electrically connected to eachother in series.
 15. A light-emitting device, comprising: a firstoptoelectronic element configured to emit a first light and comprising:a blue light-emitting diode chip having a first top surface, a firstbottom surface, and a side surface between the first top surface and thefirst bottom surface and a first wavelength converter arranged on thefirst top surface and substantially not covering the first bottomsurface; and a plurality of second optoelectronic elements comprising ared light-emitting diode chip or a green light-emitting diode chipconfigured to emit a second light having a wavelength longer than thatof the first light and having a second bottom surface lower than thefirst bottom surface in a view from the first side surface.
 16. Thelight-emitting device of claim 15, further comprising a carrier whichcomprises a first region on which the first optoelectronic element isarranged, and a second region on which the plurality of secondoptoelectronic elements is arranged, wherein the first regionsubstantially surrounds the second region.
 17. A light-emitting device,comprising: a first optoelectronic element configured to emit a firstlight and comprising: a blue light-emitting diode chip having a firsttop surface, a first bottom surface, and a side surface between thefirst top surface and the first bottom surface; and a first wavelengthconverter arranged on the first top surface and substantially notcovering the first bottom surface; and a plurality of secondoptoelectronic elements configured to emit a second light having awavelength longer than that of the first light and having a secondbottom surface lower than the first bottom surface in a view from thefirst side surface; one or more second wavelength converters arranged onat least one of the plurality of the second optoelectronic elements. 18.The light-emitting device of claim 17, wherein the first wavelengthconverter comprises a yellow wavelength converter, the second wavelengthconverter comprises a red wavelength converter.
 19. The light-emittingdevice of claim 17, further comprising a carrier which comprises a firstregion on which the first optoelectronic element is arranged, and asecond region on which the plurality of second optoelectronic elementsis arranged, wherein the first region substantially surrounds the secondregion.